One of the big problems of ID and the irreproducible complexity argument is this. If life is so complicated that it needed a designer, then, in order to design the complexity of living things, said Designer must have a similar or higher level of complexity. From whence did that complexity originate. Also, how did a Designer create the various forms of life with their basic body plans. What mechanism or force in nature accomplished this. After all if a Designer did this for life on earth, then man can do the same thing, given the knowledge and resources.
The other problem is that a Designer may 'fit the facts' as you say, but offers no testable predictions like evolution does. Nor is there any test that can show ID is false. Every theory in science has testable hypotheses that can shoot it down. Evolution has withstood, to this time, that challenge. ID does not permit that challenge.
Lewontin has admitted that modern science won't let in creative acts by an outside agency, because it is not of the paradigm of raw, untrammelled "nature" which is widely accepted by many observers and experimenters.
And on that note, the Designer, for ID to be science, must be a part of nature. If the designer can interact with the universe, then the Designer is, in some way, a part of our universe and is part of the natural world. Even humans are part of that natural world.
A good philosophical question to ask, is this... Is the realm of "nature" only what we can observe (by any purely physical means), or is "nature" that which exists, whether we can observe it or not?
That is one of the axioms of science. For something to be observable, it must be detectable. In order to be observed, it must have some interaction in the physical universe. If it cannot interact with the physical universe, it is not observable. If it is not observable, then how can it's existence be determined? It is indeed a good philosophical question, but it is not a scientific question.
One of the big problems of ID and the irreproducible complexity argument is this. If life is so complicated that it needed a designer, then, in order to design the complexity of living things, said Designer must have a similar or higher level of complexity. From whence did that complexity originate.
And is it turtles all the way down, then?
The "ID postulate" (it doesn't even rise to the level of "theory") doesn't explain anything at all, it just pushes it back a level so it can be swept under the rug -- while creating even more problems than it "resolves".